Folding-loop antenna



M. W. STAVRUM ET AL FOLDING LOOP ANTENNA Filed Aug. 25; 1924 28 mvznToRs mmtavmm R.L.O\5or\ BY m ATTORNEYS Patented Oct. 27, 1925,'

UNITED STATES PATENT OFFICE.

MAURICE W. STAVRUM, ROBERT In. OLSON, AND WALLACE H. BERRY, 0F CHICAGO, ILLINOIS.

FOLDING-LOOP ANTENNA.

Application filed August 25, 1924. Serial No. 734,021.

To all whom t may concer/ri.'

Be it known that we, MAURICE W. S'rAv- RUM, ROBERT L. OLSON, and I/VALLACE H. BERRY, citizens of the United States, and residents of Chicago, in lthe county of Cook and State of Illinois, have invented a new and useful Improvement in a F olding-Loop Antenna, of which the following is a full, clear, and exact description.

Our invention relates to improvements in folding loop antenna, and it consists in the combinations, constructions, and arrangements herein described and claimed. I

An object of our invention is to provide a folding loop antenna which may be folded up or extended quickly and easily, and in which the wires are held normally taut when the loop is extended.

A further object of our invention is to provide an'antenna` of the character described in which a bank-winding of the t-urns of wire thereupon is accomplished thereby reducing the distributed capacity of the antenna to a minimum.

A further object of our invention is to provide a device of the character described in which an especially novel arrangement of parts is provided by means of which bank-winding oft-he turns of wire on the? antenna does not in any way hinder the symmetrical arrangement of the turns in the appearance of the loop. This is accomplished bythe provision of a double comb at the lower arm of the supporting frame.

A further object of our invention is to provide a device of the character describedl in which a novel arrangement of the wire comprising the loop is accomplished so as to materially reduce the width of the loop.

Other objectsand advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

Our invention is illustrated'in the accompanying drawings forming a part of this application in which: l

Figure 1 is a front elevation of an embodiment of our invention,

Figure 1 is an enlarged fragmentary elevation of a part of the mechanism YShown in Figure 1,

A further object of our invention to provide a device that is extremely simple in Figure 3 is an enlarged view along the line 8 3 of Figure 1,

Figure 4 is an enlarged elevation of a pat of the mechanism shown in Figure 1, an

Figure 5 is a sectional view along the line 5-5 of Figure 4.

In carrying out our invention we make use of a base member 1, having a metal plate 2 centrally located on the upper surface thereof, and provided with a socket in the center of the plate extending into the base portion 1,as shown in dotted lines in Figure 4. A pair of binding posts 4: and 5 are mounted upon the base member 1.

Our improved folding loop antenna consists ina folding frame, combs carried by said frame. a flexible wire supported by the combs.

The folding frame consists in four norinally radial arms, 6, 7, 8, and 9, in Figure 1. The arm 6 is the longest of the four arms, and is disposed at the lower end of the frame. A tubular metal sheath 10 encompasses the lowermost end of the arm 6 and a depending shaft 11 (see dotted lines) is provided at the lower extremity of the arm. This shaft is arranged to be received in the socket 3 so that the frame may turn freely upon the base l.

The arms` 6 and 8 are hingedly secured to one another by the provision of a link 12 which is constructed of fiber or bakelite, pivotally connected with the arms 6 and S by the provision of shafts 13 extending through bifurcated portions 14 of the arms 6 and 8, in which the link 12 is partially received.

A metal hub member 15, forming a hub for the arms 6 to 9 inclusive when the frame is extended, is slidably mounted upon the normally aligned arms 6 to 8.

When the hub member 15 is in the position shown in Figure 2 and is arrested from further downward movement by means of a stop 16 secured to the arm 6, the frame is in position for final contraction when the arm 8 is held downwardly against the arm 6.

When the hub member 15 is in the position shown in Figure 1, movement of the arms 6 and 8 relative to one another is precluded and these arms are held in rigid axial alignment with one another as long as the hub member remains in this position. This is due to the fact that the hub member l 20:5therupward movement-'bt 'the hub 15, and a of the lWinding.

and. thus -mar the -symmetricakaraangement By centining"l the crossing of the Wire to two points closely adjacent to one. another `We .have VgreatlyV enhanced the .appearance, as' Well as the`efiiciency'of the loop. Y ,r Jlromqithe foregoing description of the various parts of the device the operation lhen the hub member is inathe.positions.fthereofrmayi-:bemreadily understood. Norshown in Figure 2, the arms 7 and 9 may 'assume the position shoivn in thisiigiure but when the hub member. is'elevated to its nor imaliposition the" arms Tand 9 must 'assume i. Y :positions diametri'callyopposite and in aXialf alignment transverse With the alignment of'.

mally our improved loop rests in the position shown in Figure 1 With .the terminals 28 and4 29fconnected swithxthe :binding posts 4 and 5f-respectively, so ,that tradlo. apparatus maybey inV turn connected .with the ,binding posts and@r receive incoming f signals inter- -iltle' lm y8' so' as to term :ap'erfect cross armiceptedbythe antenna. i Because otthe'bankn frame. ..\..A lstop 'members220,.-snnilar-to the stop` member 16, isproif'ided` on the arm S to limit spring: pressed: balli 21 is disposed uponthe :r arm. Siand arranged to'.engage'with` an'fopenn E 4ing1221through the side avail' ofY the? tubular fp'oiit'ion 17':y of thehub 15 when thehub 15'.- is in thelposition.shown'in'liigure 1. f VMzeansff ator- 'supportingy ai banlewound' il flexible antenna'-fwii'e' isprovided'by` eombsir 231 carriedfaft the fouterend ofthe arms 7, 8 and 9. These combs are constructed of? `."Qfibakelite or other: suitable materialfand have? seven shorty slots24f at equal distances 'tromi ffoneianotheriextending tow-ard `the hub 15.)5 Seven-.longenslots25 disposedfbetween the -"slots24respectively arev also provided.

"The: dil'ierence 'bet-Ween' the'depth' of' the ,1 '.s'l`otfs2t` and 25@ determines th'cdistance be-` tween.; the?. innert'fand' outer portion' of thea lil doubleWinding,laszshown: in Figure e. Inti: Werder to permit ithebanir-WindingV ot-the Wire 40 upon the combs 23 withoutidestroying the:V F symmetrical'. appearanceland arrangement oii: I ythe Winding-Weemploy two combs26fand 27 idn-i'ti'cal in" 'structure I'Whiclr'fare secured y, at q feach side of." the'ffarni'f 6fia'tljacent tothe lflvsh'eath 10. Y v

'These cinbsjy 26:1 and 2'1"@ 'zare provided with 2- .'sl'ots identical to Ithe fslots ini the comb 23,

EWinding: ofthe Wires of. 'the loopfitheeistributed 'capacity of theloo-p Will-be reduced to a minimum and the vloop fwill'therefore rfunotion with a: high'degree' otleiiiciency.

The"V device Will bes'pleasingf to--fthe eye vrbecause of; the perfect symmetry of the varms 6 to 9 inclusive, and the :tact that; the Winding's upon thei'coinbs are .uniform through- "outfA Vhen it is desired; to vcollapse the loop',

as in'rca'rrying: tromuone point tofianother or the* like, itfwill be necessary.- t'o manually lower the hub 15 tothe*positionshown in Figure 2, i.' e.,.fagafinst-the stop member 16. rIhis .Willperi'nit the arm 8 tobe moved: substantially'- parallel with the arm (i5-by? virtue.

of.tlielink.-12.The arms .Tand 9-Will in- Iclineiupwardlyi as shown inlFigure'2 so that the frame willfcollapse into a .spacefslightly longer 'than the'lengthet :the ayrm 6. i Another vmostfifimpontant advantage.- attainedfby thestr-uetfurefand arrangement of the wvires in our improved loop antenna is that .a in aximunrinductanceinthe AWinding ais'provi'ded with a minimunramount o'ffrvire, thus 'greatly increasing: the efficiency-ot the loop.

It fvvill be :noted: that in foldingtthe arms Zi 4fand 9 'upwardlyl relative to the Vhub inemfberflathat the portions'of-the-Winding bel'ftfwee'n the combs l26 and 27 .and :the :combs 23 non the-arms Tand '9 are'held so as'to mainlexcept that seven slots are provided in the tainnthcl Wires. insubstantiallyIpfarallel ar- V(-305 3d betweentheieoinbs26xand;27, as :shown in Figures and .'If it averefnotrfor. this constructioni the fcrossingifrom theainnerunrest:- iwindlng.: to :i the outermost .zvvindingf7 'izwouldfnecessarilyz 1occun between: l the :f arms .i

frangement, atherel'iy precluding the possibiliity unintentional overlapping' ofthe turns,

,which Would-cause strain to theframevhen extended and uvhichf might become so. entangledr-aslto Vcause consideialetrouble in settinggfup'*the loop fonuse.

l'lhefportions of-'the `Wire between the comb onfthe' arm y8 .and the combs' onthe'arms 7 and a9 areheldin substantiallyparallel relaw'tion with one another, thus preventing the overkapping of fthe. turns onthis .portion of the loop when the device isffolded. `"veaclaini:

1. A loop antenna'x offfthecharacter;V deseribedacomprising aafolding trama;` combs carried.-by-said.f frame, @and al` plurality of turns .0f Wire bank-Wound upon. said combs.

2. A loop antenna of the Character described comprising a frame, combs carried by said frame having a plurality of short and long slots alternately formed therein, and a plurality of turns of wire wound upon said combs and received in said slots, whereby half of the turns may lie concentric with and at a short distance from the remaining half of the turns.

3. A loop antenna of the character described comprising a frame, combs carried by said frame having a plurality ot' short and long slots alternately formed therein, and a plurality of turns of wire wound upon said combs and received in said slots, whereby every second turn may lie concentric with and at a short dist-ance from the remaining turns.

4. A folding loop antenna of the character described comprising a pair of arms, a link for pivotally connecting said arms to one another in normal axial alignment and permitting the movement of one arm parallel with the remaining arm, at will, a hub member slidably supported upon said arms,

a pair of arms pivotally secured to said hub and extending outwardly from opposite sides of said hub, and combs carried by the outer ends of each of the arms for supporting the flexible wire thereupon.

5. A folding loop antenna of the character described comprising a pair of arms, a link for pivotally connecting said arms to one another in normal axial alignment and permitting the movement of one arm parallel with the remaining arm, at will, a hub member slidably supported upon said arms, a pair of arms pivotally secured to said hub and extending outwardly from opposite sides of said hub, and combs carried by the outer ends of each of the arms for supporting the flexible wire thereupon, said hub being permitted to move along said linked arms so as to partially encompass each of the linked arms, thereby precluding movement of said arms relative to one another, at will.

MAURICE lV. STAVRUM. ROBERT L. OLSON. VVALLAOE H. BERRY. 

